The biggest hurdle I have is trying to remove the metal rails without damage as they are still good and worth re using with a polish up. I am going to attempt to put a notch in the head of the twist nail with a dremel so I can hopefully get a screwdriver to turn it enough to get a grip with pliers, I will let you know how this works out.. 

The easiest way for me it to centre punch each nail and then carefully drill the heads off.
Once the rails are off I just use some wirecutters to pull them out.